Jarring tool



E. BURNS JARRING TOOL Nov. 26, 1940.

Filed July 11, 1959 2 Sheets-Sheet l Nov. 26, 1940.

Filed July l1, 1939 2 Sheets-Sheet 2 5 3 Z 3 4 3 8 607 7 4 6 j; f 2 f 5 9 0 j i 7, f l 3 .LJ f4 2 2 2 MM2 @u 20 y 4 4 3 3 4 o Z 3 M. l 2 QJ 7 6 f 4 u l 4 7 m. o 4 2 2 4 3 4 4 /lV VEN TOI? www p M m .m Nm w@ CL Patented Nov. 26, 1940 VUNITED sTATEs JAaaING Tool.

Erwin Burns, Los Angeles, Calif., assignor of onehalf to Harry P. Wickersham, Whittier, Calif.

Application July 11, 1939, Serial No. 283,823

6 Claims.

This invention relates to oil well tools and particularly pertains to a jarring tool.

In various drilling operations it often occurs that the drill-string is twisted off in the hole or 5 that some tool becomes accidentally lodged in thehole and must be removed. This is usually accomplished by engaging the lodged object With a shing tool and then imposing a jarring force to the shing tool in a manner to act to dislodge the object. Various types of well jars have been designed, some of them operate mechanically and their hammer and anvil sections are held apart and released by mechanical means controlled on the top of the well. Other types of jars have hydraulic action so that when a hydraulic pressure is imposed upon parts of the jar a jarring action will be created and in some instances the jarring parts will be released.l In the operation of well jars of hydraulically latched type one of the particular problems is to maintain parts of the jar in a fluid-tight condition, since the pressure exerted upon the fluid producting the latching action is of great magnitude and the hydraulic pressure of the column of iluid within the well and Within which the jar is submerged is likewise of great magnitude.

It is the principal object of the present invention, therefore, to provide a well jar of the hydraulically latched type and within which a quantity of drilling fluid from the well is temporarily entrapped to produce a latching action, the said drilling iluid discharging directly back into the well in an unrestricted flow and the moving parts being at all times hydraulically balanced. The present invention contemplates the provision of a well jar including a mandrel section and a barrel section, one of which sections carries an anvil and the other of which sections carries a hammer. The sections are slightly linked together and are provided with an intermediate chamber within which drilling uid from the well may be entrapped and from which it is discharged by the tension imposed upon the drill-string to permit release of the mandrel and barrel and to produce a blow between the hammer and the anvil in proportion to the magnitude of tension applied to the drillstring at the top of the Well.

The invention is illustrated by way of ex- 50 ample in the accompanying drawings, in which:

Figure 1 is a view in elevation showing the assembled well jar.

Fig. 2 is a view in central longitudinal section showing the well jar with its parts in their .-55 hydraulically latched position.

(Cl. Z55-27) Fig. 3 is a view in central longitudinal section similar to Fig. 2 showing the well jar with its parts in an intermediate position and at substantially the point at which the jar releases.

Fig. 4 is a view in central longitudinal section s showing the jar in its impact position.

Referring more particularly to the drawings, I0 indicates a drill-string which is suspended from suitable means 'in the derrick of a well and which is here shown as carrying a threaded box II at its lower end. Mounted within the box II is the pin I2 of a well jar structure, generally indicated at I3. The pin is formed as a part of an upper sub I4 which has a circular passageway I5 therethrough and a threaded counter-bore I8 at its lower end. The threaded counter-bore I6 15 receives the upper threaded end 0f a tubular mandrel I1. The mandrel I1 is .here shown as extending "downwardly through a barrel I8. The upper end of the barrel I8 is fitted with an anvil collar I9 which is threaded onto the barrel and zo is provided with an anvil face 20. A central passageway 2I is formed through the collar I9 to receive the tubular mandrel I1. The mandrel I1 is formed at its lower end with an enlarged head 22. Secured within the circumferential faces of this head is a pair of diametrically opposed keys 23. The keys 23 extend into slotted openings 24 in the diametrically opposite side Walls of the barrel I8. At right-angles to the plane of the openings 24 in the wall of the barrel I8 are slotted openings 25 through which well iiuid may pass as will be hereinafter described.

The mandrel I1 is formed with a central circulation bore 26, the lower end of which terminates in a threaded counter-bore 21. The counter-bore 21 receives the threaded end of a continuing mandrel 28. This mandrel has a central circulating passageway 29 through it 'which permits free flow of uid at all times. The continuing mandrel 2s is formed with sections of two diameters, an upper section 30 which is of larger diameter and extends through a bushing 3I carried by an inner shoulder 32 of the barrel I8. A slight clearance space 33 exists 5 between the circumferential face of the bore of the bushing and the outer circumferential face of the portion 30 of the mandrel extension 28. Below the mandrel portion 30 is a reduced portion 34. Mounted on the lower end of the por- 5 tion 34 of the mandrel section 28 is a piston structure. This comprises a metallic cup 35 formed with a cylindrical flange 3B. Disposed y 4between the iiange 36 and the wall of the bore 31 of the barrel is a packing element 38 which pro- 55 duces a duid-tight seal betweenthe cylindrical face of the iiange 3l and the cylindrical i'aceot the wall of the bore I1. The lower end of this cup abuts against a shoulder 3l formed on the mandrel extension 2l and it is held in this position by a lock nut 4t which engages the threaded end oi' the mandrel extension 2l. l'iormed through the end wall of the cup are ducts 4l. Resting against the upper ends ot these ducts is a valve ring 42 by which the ducts are closed during a certain operation of the Jar.

Spaced from the shoulder 3l and overhanging the valve ring 42- is a retaining shoulder 43. This retaining shoulder limits the movement of the valve ring 42 away from its seat. Attention is also directed to the fact that the' valve ring has a sliding iit within the cup 3| and that it is guided toward and away from its seated position. The lower end of the valve barrel is internally threaded, as indicated at 44, and receives the threaded end 45 of another drill-string or of a fishing tool connection. Attention is directed to the tact that this member 4l has a central iiuid passageway 4t therethrough. Thus at all times a continuous passage ot iluid may circulate through the mandrel I1, the mandrel extension 2B and the drill-string sections at the opposite ends thereof.

It will be noted that the bore I1 forms a oompartment 41 within which fluid may be entrapped. This entrapment of huid takes place between the piston element 3i and the shoulder structure 32 when the enlarged portion 3| of the mandrel extends into or through the bore Il of the bushing 3l.

In operation of the present invention the structure is assembled as shown in the drawings. The lower drill-string section 4l may be ntted with a fishing tool and the upper drill-string section il may be connected with the draw works o! a well rig. The device is then lowered into the well. During this lowering operation the mandrel l1 and the barrel i8 are in a collapsed position and the head 22 of the mandrel section II extends downwardly into a counter-bore seat 43 which occurs above the bushing 3|. It will be evident that the mandrel and the barrel are held against relative rotational movement by the keys 2l extending into the keyways 24 and that the lower end of the barrel and the lower drill-string section with the iishing tool may be readily manipulated. It is to be understood that circulation is being maintained through the well jar at all times since the passageway 2t of the upper mandrel section i1 communicates with the passageway 2l of the lower mandrel section 2l. The passageway 29 is open at its lower end and discharges fluid into the barrel as well as into the lower drill-string section.

When the jar is in its collapsed condition, as particularly shown in Fig. 2 oi the drawings. the enlarged portion 3D of the lower mandrel section 28 substantially lls the opening ll through the bushing 3| and substantially seals the compartment 41 occurring between the barrel and the piston 35. The circulating iluid will at this time pass downwardly through the mandrel and after filling the lower drill-string section will now upwardly in the passageways 4i of the piston 3l. This will lift the valve ring 42 from its sealing position over the upper ends of the ports 4| and permit the compartment 41 to ll with the huid of the well. It is to be understood also that a similar action will take place when the well jar has been submerged in the column of iluid within a well aaaasss to a depth greater than the upper end oi the compartment 41.

Attention is also directed to the fact that when the well jar is completely submerged in drilling iiuid the hydrostatic pressure exerted by the iluid will balance the moving parts of the well Jar and the piston 3l at all times since the openings 24 and 2l in the barrel permit free access of drilling fluid to the upper end ot the passageway 33 leading to the compartment 44, and direct communication of the compartment 41 with the interior of the drill-string insures that the piston Il will be in eflect moving in a full column ot drilling iiuid at all times. The only resistance to this movement is the action produced in forcing the iluid from the compartment 41 through the bore $3 during the time that this bore is occupied by the enlarged portion 3l ot the mandrel section 2l, as shown in Fig. 2 of the drawings.

When a jarring action is to be produced the compartment 41 will be filled with nuid, as previously described, and the parts will be in the position as shown in Fig. 2 of the drawings, at which time the well Jar will be in its latched position due to the coniined quantity of drilling iluid entrapped within the compartment 41 between the partition 22 and the piston 3l. A desired strain is then placed on the drill-string. This strain will act to create stretch in the drillstring. When a predetermined stretch has been placed inthe drill-string the upper end oi the drillstring is held and the drill-string acts to restore itself to its normal unstretched condition. During this action the barrel i8 is held against movement and the enlarged portion Il of the mandrel is gradually drawn through the opening 3l in the bushing Il while the iluid from the compartment 41 is displaced 'as it is forced through the passageway occurring between the bushing 3| and the enlarged portion 30 of the mandrel. This displacement of iluid is brought about due to the fact that the valve ring 42 is on its seat and closes the ports 4i, and that the piston 3i is moving upwardly and acting against the entrapped quantity oi drilling iiuid within the compartment 41.

When the enlarged portion 3l o! the mandrel section 24 moves so that its lower edge Il' is above and in a position of clearance with the bushing 3i then the restricted portion 34 of the mandrel section 28 will be in register with and extending through the bushing 3| to create the relatively large annular passageway Il which establishes communication between the compartment 41 and the column of fluid in the well bore. 'I'he result will be that the existing tension in the drill-string will act violently to pull the mandrei upwardly and will cause the face 22' of the hammer to strike the anvil face 2l. This will deliver a blow to the barrel II, and since the barrel is indirectly connected to the fishing tool a jarring blow will be delivered to the tlsh.

Attention is directed to the fact that during this rapid and violent movement of the piston 3l it is hydrostatically balanced by the column ot fluid within which it is submerged. Thus, it is insured that the upward movement of the piston will be in a iluid under substantially balanced pressure, and that a maximum blow will occur between the hammer and the anvil due to the tact that the iluid will not dampen the action of the hammer as it strikes. II it is desired to relatch the jar the tension is removed from the drill-string so that the piston 3i will settle in the compartment 41 with the result that iluid will ilow into the compartment 41 while the mandrel section 28 is moving downwardly until the enlarged` portion 30 is in register with the bushing 3l, after which fluid will flow upwardly through the ports Il in the piston as thevalve ring I2 is lifted.

In analyzing the construction of the well Jar with which the present invention is concerned and its mode of operation, it will be seen that the problems of providing a packing for the piston which will withstand the action ,of external hydrostatic pressure as created by the uid in the well bore is limited since the piston is substantially balanced at all times by the fluid in the well and merely withstands the excess pressure produced during the compression stroke while displacing the drilling fluid from the compartment I1 through the bushing 3l and around the enlarged mandrel section 30. It will also be seen that few moving parts are required, none of which are subjected to excessive wear, and thatthere is no problem involved in maintaining a iiuid seal for a separate isolated volume of incompressible ,fluid as is present in other types of hydraulically locked jars. It is also apparent that since all of the moving parts are constantly submerged within the drilling uid in the well and that the drilling iiuid is free to iiow through all of these parts in flow and counter-flow, that there is no possibility for the Well jar to sandup and its parts become thus abraded and worn.

It will thus be seen that the invention here disclosed comprises a well jar structure involving the use of a minimum number of moving` parts, none of which are subjected to excessive and detrimental wear, and which jar may be readily latched and released while operating in the drilling iiuid and by the use of drilling iiuid within which it is submerged.

While I have shown the preferred form of my invention as now known to me, it will be understood that various changes may be made in combination, construction and arrangement of parts by those skilled in the art, without departing from the spirit of my invention as claimed.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A hydraulic well jar comprising a barrel, a tubular mandrel reciprocating therein, said barrel and mandrel being capable of attachment to drill-string sections whereby a continuous fluid circulation may take place through the drillstring sections, the mandrel and the barrel, a fluid entrapment space within the barrel -in communication with the fluid circulating through the drill-string, a restricted passageway at the upper end of said fluid space and in constant communication with the fluid within which the jar is submerged and through which passageway the mandrel reciprocates, and an enlarged portion on said mandrel adapted to register with said passageway when the mandrel and barrel are in collapsed position with relation to each other and whereby a restricted annular orifice will be formed through which fluid may be displaced from the entrapment space as tension is exerted between the barrel and mandrel.

2. A hydraulic well jar comprising a barrel, a tubular mandrel reciprocating therein, said barrel and mandrel being capable of attachment to drill-string sections whereby a continuous fluid circulation may take place through the drillstring sections, the mandrel and the barrel, a fluid entrapment space within the barrel in communication with the uid circulating through the drill-string, a restricted passageway at the upper end of said fluid space and in constant communication with the fluid within which the jar is submerged and through which passageway the mandrel reciprocates, an enlarged portion on said mandrel adapted to register with said passageway when the mandrel andbarrel are in collapsed position with relation to each other and whereby a restricted annular orifice will be formed through which uid may be displaced from the entrapment space as tension is exerted between the barrel and mandrel,.and anvil members carried by the barrel and mandrel and adapted to strike each other when the enlarged portion of the mandrel has been retracted from. register with the communicating pasageway to the entrapment space.

3. A hydraulic well jar comprising a barrel, a tubular mandrel reciprocating therein, said barrel and mandrel being capable of attachment to drill-string sections whereby a continuous uid' circulation may take place through the drillstring sections, the mandrel and the barrel, a uid entrapment space within the barrel in communication with the fluid circulating through the drill-string, a restricted passageway at the upper end of said fluid space and in constant communication with the fluid within which the jar is submerged and through which pasageway the mandrel reciprocates, an enlarged portion on said mandrel adapted to register with said passageway when the mandrel and barrel are in collapsed position with relation to each other and whereby a restricted annular orifice.wil1 be formed through which fluid may be displaced from the entrapment space as tension is exerted between the barrel and mandrel, and anvil members carried by the barrel and mandrel and adapted to strike each other when the enlarged portion of the mandrel has been retracted from register with the communicating passageway to the entrapment space, the space occurring between the hammer and anvil faces being at all times in free communication with the well bore.

4. A hydraulic well jar comprising a barrel. a tubular mandrel reciprocating therein, said barrel and mandrel being capable of attachment to drill-string sections whereby a continuous iiuid circulation may take place through the drillstring sections, the mandrel and the barrel, a uid entrapment space within the barrel in communication with the uid circulating through the drill-string, a restricted passageway at the Vupper end of said uid space and in constant communication with the fluid within which the jar is submerged and through which passageway the mandrel reciprocates, an enlarged portion on said mandrel adapted to register with said passageway when the mandrel and barrel are in collapsed position with relation to each other and whereby a restricted annular orice will be formed through which fluid may be displaced from the entrapment space as tension is exerted between the barrel and mandrel, anvil members carried by the barrel and mandrel and adapted to strike each other when the enlarged portion of the mandrel has been retracted from register with the communicating passageway to the entrapment space, and check valve means acting to permit a by-pass of uid around the piston as the piston moves to the collapsed position of the jar and to prevent said by-pass as the piston moves toward its impact position.

5. A hydraulic well jar comprising a barrel, a tubular mandrel reciprocating therein, said barrel and mandrel being capable of attachment to drill-string sections whereby a continuous :duid circulation may take place through the drillstring sections, the mandrel and the barrel, a

' uid entrapment space within the barrel in. communication with the iluid circulating through the drill-string, a restricted passageway at the upper end of said iluid space and in constant communication with the uid within which the jar is submerged and through which passageway the mandrel reciprocates, an enlarged portion on said mandrel adaptedto register with said passageway when the mandrel and barrelare in collapsed position with relation to each other and whereby a restricted annular orifice will be formed through which fluid may be displaced from the entrapment space as tension is exertedbetween the barrel and mandrel, anvil members carried by the barrel and mandrel and adapted to strike each other when the enlarged portion of the mandrel has been retracted from register with the communicating passageway to the entrapment space, check valve means acting to permit a by-pass of iluid around the piston as the piston moves to the collapsed position of the jar and to prevent said by-pass as the piston moves toward its impact position, and inter-engaging means between the mandrel and the barrel whereby said members are locked against relative rotational movement and are free to move longitudinally with relation to each other.

6. A hydraulic well jar adapted to be interposed between tubular lengths of drill-string,

which Jar includes a tubular mandrel connected to one length of said drill-string and a tubular barrel within which it reciprocates and which is connected to the other length of drill-string, a fluid entrapment chamber formed in the barrel, a piston carried by the mandrel and reciprocating within said chamber, means permitting a free circulation of :tluid through the drill-string, the mandrel and the barrel and into the uid entrapment chamber on one side of the piston, means permitting a free circulation of iiud through the barrel and to the well bore whereby the piston will be substantially fluid-balanced at all times, said last named means including a `restricted opening within the barrel from the entrapment chamber to the exterior thereof, and an enlarged portion upon the mandrel adapted to register with said restricted passageway when the jar is in its collapsed position and whereby a relatively small annular space will occur between the wall of the passageway and the surface of said enlarged mandrel portion and 'through which iiuid may be displaced from said entrapment chamber to the well bore under tension created between the barrel and the mandrel.

ERWIN BURNS. 

